java work

Prevayler in java & the dangers of object serialization

Today we've been hit by something which I thought wasn't possible : our project is build around EJBs. We use eclipse as an IDE. Our EJBs are built using ANT and javac while Eclipse has its own compiler.
We have tests which we run from Eclipse. Two of our value objects create marshallingexceptions when they are exchanged between client (in eclipse) and server (javac-compiled EJBs). This got solved by setting the serial UID manually. I'm surprised the JLS doesen't specify that the same code compiled by different compilers must give the same serial version ! In fact different versions of the same compiler can give different results and JBuilder 5 seemed to be snagged by that, there are FAQs about it and someone even created a bug in Eclipse which wasn WONTFIXed... see #10104.

So here's what I've been thinking... I've been reading about prevayler... it takes consistent snapshots of the system. It's currently implemented using object serialization... ok, let's imagine I'm running JDK1.3 and I want to update to 1.4. I shutdown the system... everything gets stored to a persistant store. I recompile the system without changing any code and start it again... given the problems we ran into, I'm pretty sure someone would run into incompatibilities... I think that's a problem... perhaps all serializable objects in Prevayler should have there serialVersionUID set manually...

my 2 cents...